Cutting sheet metal



R. D. MERSHON.

. CUTTING SHEET METAL.

APPLICATION FILED APR. 3. 1911. RENEWED JULY 18. 1919.

Patented Mar. 2, 1920.

6 m w n 5 RALPH ID. MERSHON, OF NEW YORK, N. Y.

CUTTING SHEET METAL.

Specification of Letters Patent.

Application filed April 3, 1917, Serial No. 159,394. Renewed July 18,1919. Serial No. 311,904.

To all whom z'tmay concern:

Be it known that I, RALPH D. MERSHON, a citizen of the United States,residing at New York, county and State of New York, have inventedcertain new and useful Improvements in Cutting Sheet Metal, of which thefollowing is a full, clear, and exact description.

In my copending application Ser. I No. 159,146, filed AprilQnd, 1917, Ihave described an electrode, for use in electrolytic condensers andother electrolytic apparatus, composed of a crimped or corrugated stripof thin sheet metal carried by a metal supporting frame. For the purposeof securely holding the sheet metal plate the upper and lower edgesthereof are grooved across the folds or corrugations, to receive theedges of the upper and lower members of the supporting frame. To makethis groove by prior methods without mashing the folds or otherwisedistorting the plate is a diflicult operation, and it is accordingly thechief object of my present invention to provide a simple method by whichthe groove can be quickly and easily out without the slightest injury tothe plate. To-this and other ends the invention consists in the novelfeatures hereinafter described.

In the accompanying drawing, Figure 1 is a side view of a portion of anelectrode having a crimped plate provided with a groove in its upperedge to receive the upper member of the supporting frame. Fig. 2 is adetail perspective view showing the up per-frame-member in the groove.Fig. 8 is also a detail perspective view, showing the grooved upper edgeof the crimped plate. Fig. 4 is a detail sectional view showing the edgeof the crimped plate inserted in a trough-shaped mold, for casting onsaid edge a block of fusible material. Fig. 5 is a detail perspectiveview showing the edge of the crimped plate and a block of fusiblematerial thereon, filling the spaces between the folds. Fig. 6 is asimilar view, showing a groove and a hole cut through the fusible blockand the folds embedded therein. 7 The plate 10 is composed of thin sheet'metal and is folded or crimped so that it may be used in a vessel orcell (not shown) of convenient size. To give it mechanical strength itis mounted in a suitable supporting frame, of which the upper crossmember is shown at 11 and one side member'at 12.

-The lower edge of the said upper member Patented Mar. 2, 1920.

extends into a groove 13 in the adjacent edge of the plate 10, whichgroove is simply a series of alined notches cut in the upper ends of thefolds or crimps.

In cutting the groove by my present method the individual folds aresupported on eachside by fusible material which fills the space betweenadjacent folds. This holds the folds apart at the proper distance. Thegroove is cut, for example by sawing, through the folds and theinterposed material, the latter serving as a support for the sheet metaland so preventing mashing of the folds and formation of heavy burs atthe edges of the out; Preferably the desired support is provided bycasting a block of the fusible material on the edge-portion of theplate, the material or substance used being one that has a lower meltingpoint than the metal of the plate. Among the various materials that canbe used I. may mention lead, zinc, or tin, or'other metal or an alloy oftwo or more of the same; or non-metallie materials and compositions, forexample sulfur, shellac, rosin, etc., with or without admixture withother substances, fusible or non-fusible. Preferably I use a mixture ofsulfur and graphite, especially with aluminum plates. In thiscomposition the graphite makes the sawing easier, partly because itpermits less sulfur to be used, and partly because of its lubricatingeflect.

The supporting block can be conveniently cast upon the crimped plate inthe following manner.

A mold is prepared in the form of a trough 14 (preferably in two or moreseparable parts) slightly deeper than the groove that is to be cut, andthe molten material is poured into the mold. The edge of the plate isthen inserted into themolten material to a point well above the pointwhere the bottom of the groove is to be. The edge of the plate,-composedof the end portions of the folds,is thus embedded in a solid block 15,Fig. 5. A groove 16, Fig. 6, can now be.

cut across the folds, as by sawing or milling, or a hole 17 can be boredthrough the folds, without distorting the same in the slightest degreeand even without leaving an appreciable bur on the edges of the thinsheet metal. then melted off, leaving the crimped plate as it wasoriginally except for the presence of the groove 13 01 hole 17, or both.

The crimped plate is then mounted in its The block of fusible materialis supporting frame, and is electrically connected to the-latter in anyconvenient and suitable manner, as by welding one or more strips l7,cutfrom the plate, to the upper member 11 of the supporting frame.

It is to be understood that the invention is not limited to the specificdetails of procedure herein described; nor is it limited to use in themanufacture of electrodes but can be used for cuttingsheet metal for"numerous other purposes. It is also to be understood that the method ofmaking the out, whether by boring, drilling, milling, sawing, or thelike, is immaterial.

I I claim 1. The method of cutting a clean aperture in sheet metalWithout distortion or material burring, comprising casting on the sheetmetal about the place where the out is to be made a block or body ofmaterial having a lower melting point to support the sheet metal,cutting the desired aperture through the cast material and thesheetmetal, and melting off the remaining cast material.

2. The method of cutting an aperture through a plurality of spacedlayers of sheet metal, comprising castlng between such layers at thepoint where the aperture is to be made a block or body of materialhaving a lower melting point to support the sheet metal whereby theseparation of the successive layers thereof will be maintained,

\ cutting the desired aperture through the 1 and into the folds thereofat the point where the aperture is to be made a block or body ofmaterial having a lower melting point to maintain the separation of thefolds and prevent distortion thereof, cutting the aperture through thecast material and the successive spaced folds of the sheet metal, andthen melting out the remaining portion of the cast body.

In testimony whereof I hereunto aflix my signature.

RALPH D. NERSHON.

